A thought on BRS

Speed limits, seat belts, ABS, airbags, crumple zones,
roll over bars, BRS, parachutes, and ejector seats
have nothing whatsoever to do with preventing accidents,
they are only there to mitigate the outcome. Every
accident has the potential to cause death or serious
injury, whether that occurs is really a matter of pure
blind chance. People are the cause of accidents and
the only way to prevent them is to edjucate so that
they do not happen. All the gadgets do is reduce the
chance of injury when we screw up.
Far too often the outcome of the accident is considered
the priority in any investigation instead of the cause.

At 14:12 27 April 2004, Tom Seim wrote:
I'm not saying this is a good tradeoff or a poor one,
but it's
disingenuous to pretend it's not there. It's equally
disingenuous to
pretend that we couldn't prevent 95% of highway fatalities
quite
easily. All it would take is a 35 mph speed limit
for divided
highways and a 17 mph speed limit for other roads
- and draconian
enforcement. It wouldn't prevent the accidents, but
it would
eliminate most of the fatalities. Of course we don't
do this because
we want to get where we are going quickly.

Michael

This has been the argument against raising the speed
limits on our
highways, ever since they were lowered by that benevolent
dictator
Jimmy Carter. The only problem, the argument is wrong!
We learned that
after raising the limits and watched the fatality rates
continue to
drop.

Common wisdom is, sometimes, uncommon nonsense.

I think the problem is tunnel vision safety analysis
by 'experts' that
vastly overrate their abilities. Part of the problem
with the speed
limits is that drivers weren't obeying the limits to
begin with.
Raising the limits merely reflected the reality of
the situation.
Draconian enforcement simply won't work, at least not
(fortunately) in
the U.S., because law enforcement works only by voluntary
compliance.
There simply are not enough cops and jails out there
to impose a law
that the vast majority of the population won't accept.
This clearly
happened with the poorly thought out national speed
limit. But there
still is a group that, even with all of the evidence
to the contrary,
thinks that it will work.

Instead, we should put the effort into things that
do work. The most
dramatic example of this is mandatory seat belt usage.
In Washington
state this became a primary law (you can be stopped
for it), which
resulted in compliance rates in the 85-90% range (instead
of 15-20%
before there was any law). No changes were required
to cars since the
belts were already there. Most people have accepted
the law, but there
is still a vociferous minority that reject it. Everybody
benefits,
besides being safer, with lower insurance rates.

Tom Seim

I still have reservations about BRS, not because of the philosophy, but I'm
not sure the engineers have all the bugs out of it. Any system that will
lower a disabled aircraft and its occupant(s) to the ground safely is a very
good thing. The short history of the Cirrus BRS is very encouraging, at
least I haven't heard of any injuries to the passengers.

I know BRS has a long and exemplary record with ultralights but they are
slow and light and usually flown by the young and able. The idea of hitting
the ground in a seated position at 20 FPS is disturbing to a 60 something
glider pilot. I know using a personal 'chute is just as problematic but I
would land with my legs under me. A broken leg is vastly better than a
broken back.

For now, personal 'chutes with egress aids like DG's NOAH look better to me.
At least this idea could be retrofitted to an older glider. The 35 pounds
or so the BRS adds to the non-flying part of the glider bothers me too.

Bill Daniels

Bill Daniels wrote:
I still have reservations about BRS, not because of the philosophy, but I'm
not sure the engineers have all the bugs out of it. Any system that will
lower a disabled aircraft and its occupant(s) to the ground safely is a very
good thing. The short history of the Cirrus BRS is very encouraging, at
least I haven't heard of any injuries to the passengers.

I know BRS has a long and exemplary record with ultralights but they are
slow and light and usually flown by the young and able. The idea of hitting
the ground in a seated position at 20 FPS is disturbing to a 60 something
glider pilot. I know using a personal 'chute is just as problematic but I
would land with my legs under me. A broken leg is vastly better than a
broken back.

I believe the current designs lower the glider nose down, and the
cockpit has to be properly designed to avoid injury to the pilot, as it
must absorb the impact. It's not a simple problem, and gliders that
aren't designed for it from the start almost surely won't be suitable
for retrofitting.


For now, personal 'chutes with egress aids like DG's NOAH look better to me.
At least this idea could be retrofitted to an older glider.

Certainly a much more practical addition!

The 35 pounds
or so the BRS adds to the non-flying part of the glider bothers me too.

It would likely reduce the allowable cockpit load.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

On Tue, 27 Apr 2004 12:07:37 -0700, Eric Greenwell
wrote:

Bill Daniels wrote:
..../....

The 35 pounds
or so the BRS adds to the non-flying part of the glider bothers me too.

It would likely reduce the allowable cockpit load.

Surely, as the BRS would be installed on or just behind the CG, it
would be more like carrying a turbo in that the cockpit load would
remain as before but the permitted amount of water ballast would be
decreased.

--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

Martin Gregorie wrote:
On Tue, 27 Apr 2004 12:07:37 -0700, Eric Greenwell
wrote:


Bill Daniels wrote:

..../....


The 35 pounds

or so the BRS adds to the non-flying part of the glider bothers me too.

It would likely reduce the allowable cockpit load.


Surely, as the BRS would be installed on or just behind the CG, it
would be more like carrying a turbo in that the cockpit load would
remain as before but the permitted amount of water ballast would be
decreased.

I simplified it a bit too much, perhaps. It would come out of the
"non-lifting parts" limit (basically the fuselage and everything in it).
Generally, the effect would be to reduce the cockpit allowed load, but
not always, depending on the exact weight of fuselage and installed
equipment. The amount of water ballast allowed would not likely change,
since it is carried by the wing (a lifting part), not the fuselage.

A glider designed to carry a motor will have a higher "non-lifting
parts" limit (perhaps from more structure, stronger lift pins, etc) than
a similar non-motorized one, in order to preserve the cockpit load.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

On Tue, 27 Apr 2004 13:39:27 -0700, Eric Greenwell
wrote:

Martin Gregorie wrote:
On Tue, 27 Apr 2004 12:07:37 -0700, Eric Greenwell
wrote:


Bill Daniels wrote:

..../....


The 35 pounds

or so the BRS adds to the non-flying part of the glider bothers me too.

It would likely reduce the allowable cockpit load.


Surely, as the BRS would be installed on or just behind the CG, it
would be more like carrying a turbo in that the cockpit load would
remain as before but the permitted amount of water ballast would be
decreased.

I simplified it a bit too much, perhaps. It would come out of the
"non-lifting parts" limit (basically the fuselage and everything in it).
Generally, the effect would be to reduce the cockpit allowed load, but
not always, depending on the exact weight of fuselage and installed
equipment. The amount of water ballast allowed would not likely change,
since it is carried by the wing (a lifting part), not the fuselage.

A glider designed to carry a motor will have a higher "non-lifting
parts" limit (perhaps from more structure, stronger lift pins, etc) than
a similar non-motorized one, in order to preserve the cockpit load.

Thanks for the explanation.

--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

Not really. For allmost every turbo equipped glider the max. total weight is
the same as the one for the pure glider, and in some cases the turbo has one
even lower. The discus 1 for example has a MTOW of 525 kg without the engine,
but with the turbo it reduced to 450 kg.

Roelant van der Bos




I simplified it a bit too much, perhaps. It would come out of the
"non-lifting parts" limit (basically the fuselage and everything in it).
Generally, the effect would be to reduce the cockpit allowed load, but
not always, depending on the exact weight of fuselage and installed
equipment. The amount of water ballast allowed would not likely change,
since it is carried by the wing (a lifting part), not the fuselage.

A glider designed to carry a motor will have a higher "non-lifting
parts" limit (perhaps from more structure, stronger lift pins, etc) than
a similar non-motorized one, in order to preserve the cockpit load.

Thanks for the explanation.

--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

"Bill Daniels" wrote in message
news:Jxvjc.42417$GR.5925024@attbi_s01...
I still have reservations about BRS, not because of the philosophy, but
I'm
not sure the engineers have all the bugs out of it. Any system that will
lower a disabled aircraft and its occupant(s) to the ground safely is a
very
good thing. The short history of the Cirrus BRS is very encouraging, at
least I haven't heard of any injuries to the passengers.

I know BRS has a long and exemplary record with ultralights but they are
slow and light and usually flown by the young and able. The idea of
hitting
the ground in a seated position at 20 FPS is disturbing to a 60 something
glider pilot. I know using a personal 'chute is just as problematic but I
would land with my legs under me. A broken leg is vastly better than a
broken back.

For now, personal 'chutes with egress aids like DG's NOAH look better to
me.
At least this idea could be retrofitted to an older glider. The 35 pounds
or so the BRS adds to the non-flying part of the glider bothers me too.

Bill Daniels
Bill,
I talked to the BRS people at the SSA convention a couple of years ago
regarding fitting one of their syatems to the Nimbus. They said no dice
because the energy absorption characteristics of the cockpit configuration,
descent rate, etc., etc., just wouldn't work.
Just as you said.
Streifeneder has been doing some certificatoin work in Germany on a retrofit
package for some ship but I do'nt remember the details. It looks like some
of the newer gliders may be taking the BRS sytem into account in in their
initial design now however.Too bad there's not an off the shelf retrofit
package.
Cheers!, Pete